The logical way to properly resolve theSouth China Sea disputes would first be to determine the ownership of the disputed islands, and then determine how much of the sea belongs to each island. However, given China’s opposition to using an international court or tribunal to resolve the disputes, and given that without a court ruling, no nation will give up its claim to the islands, there’s little prospect of resolving the question of island ownership any time soon.

The problem is that the claimants are stuck indefinitely at the first step, which means they never get around to defining the maritime space belonging to each island. This allows China to act as if most of the South China Sea were disputed, thus bringing the James Shoal, part of the Natuna Sea, the Reed Bank, the Vanguard Bank and Blocks 127 and 128 off the coast of Vietnam into the category of ‘disputed territory.’
Given the problems with the conventional approach, then, it’s imperative that Southeast Asian parties to the dispute find an alternative method – rather than wait for the answer to the question of island ownership, the claimants should do the reverse and first define the extent of the maritime space belonging to each disputed island. This can be done through negotiations or by submitting the question to an international court or tribunal.

How much maritime space belongs to an island obviously depends on the physical geography of that island when compared with surrounding territories, not on who owns it. Therefore, it should be possible to address this question independently of, and without prejudice to, the issue of island ownership.
Once the extent of the maritime space belonging to each island has been defined, the extent of the South China Sea disputes is also defined: those disputes comprise the disputed islands and the area of the sea that actually belongs to each island.
Although defining the extent of the South China Sea disputes doesn’t in itself resolve the problem, it would be the most significant progress forward in decades in managing this issue. For example, while much has been said about the Declaration of Conduct from 2002 between ASEAN and China, as well as on the idea of a new Code of Conduct, these instruments both have a fundamental shortcoming: they don’t define the extent of the disputes. Clearly, different action is necessary depending on whether a disputed or an undisputed area is concerned. It’s therefore necessary to define the extent of the disputed areas before devising the best approach for each area.
As another example, consider China’s proposal of shelving the sovereignty disputes and jointly exploiting the resources. In theory, that sounds like a reasonable proposal. In practice, it’s only reasonable if the joint exploitation is in disputed areas – the problem being, of course, that the extent of the disputed areas haven’t been agreed on by all parties. At the moment, China is demanding joint exploitation arbitrarily, in areas that are up to 700 nautical miles from the coast of China, but which are well within the 200 nautical mile EEZ of the coasts of the Philippines and Vietnam, and closer to those nations’ undisputed territories than to the disputed Paracels and Spratlys. This is clearly unreasonable, and it’s why China’s seemingly reasonable proposal isn’t actually workable. Defining the disputed area in a way that is consistent with international law is a prerequisite for any joint exploration.
Ultimately, defining the extent of the disputed areas would also improve security in the South China Sea. First, the disputes would be contained in clearly marked areas, rather than being expanded arbitrarily. Second, agreeing on what is actually in dispute would reduce mismatched expectations among claimants, which would, in turn, reduce tensions and the likelihood of incidents involving the use of force.
Huy Duong contributes articles on the South China Sea to several news outlets including the BBC and Vietnam's online publication VietNamNet.